Hepatitis B is a virus which causes an infection of your liver. Usually it goes away after some period of time but in some cases it could stay for a very long time. During this time Heptitis B could make serious damages to your liver.
You could be infected in every stage of your life by blood and body fluids. Many people don't know they could have Hepatitis B because it's symptomless. Children's and older people skin could become yellow after up to 6 months.
Untreated and chronic infection could lead to liver cancer.